This invention relates especially to commercial vehicles, and particularly to dual wheel brake maintenance on heavy trucks and traitors or the like. Brakes are a major maintenance problem in the operation of trucks and traitors. Unfortunately, due to weight, awkwardness and size of a set of dual truck wheels, brake maintenance is a strenuous and most difficult safety task one must perform. That is, the truck owner and/or operator must maintain safe brakes. To work upon the brake mechanism for example, one must remove the brake drum in order to gain access to the brake mechanism, there being two basic types of brake-to-hub arrangements; inboard and outboard. Also, the brake drum can be replaced by a brake disc. However, state of the art is for the most part of the drum brake type. And, the brake mechanism and wheels whether single or dual are applied to either drive or non-drive axles. For example, brake and wheel assemblies are applied to tractors as well as to trailers, and to steering axles as well. It is to be understood that it is the brake mechanism and the wheel assembly of whatever type to which this invention is directed, and attachment thereof by means of an axle or spindle or the equivalent.
The most common and older brake-wheel assembly is the inboard hub type wherein the brake drum mounts onto the inside of the hub, in which case the hub must be removed in order to gain access to the brake mechanism. The other most common and newer brake-wheel assembly is the outboard hub type wherein the brake drum mounts onto the outside of the hub, in which case the wheel with the brake drum must be removed in order to gain access to the brake mechansim, leaving the wheel hub in place on the axle or spindle. It is a general object of this invention to provide apparatus for access to brake mechanisms of each and all of the aforementioned types of brake-wheel assemblies.
Many if not most independent truck owners do their own brake maintenance. Optimum conditions for brake access and repair is thought to require a flat hard and smooth surface such as a concrete slab or horizontal floor upon which to park the truck axle to be inspected and/or repaired. However, inspection and/or repair must often be done on-site or on the road and away from the convenience of a suitable facility. Therefore, is is an object of this imnvention to provide an apparatus that is self sufficient and not reliant upon a specialized facility.
When doing repair work on inboard type wheel hubs, a prior art tool, if done on a concrete slab or steel plate, is a Wheel Dolly. The Wheel Dolly has a frame with a set of arms adjustable to cradle and support a wheel or set of duals. The Dolly has a set of three or four caster type wheels to roll upon a flat preferably horizontal surface for parallel placement of the dual wheel axis in alignment with the truck axle, for replaceable removal of the duals and exposure of the brake drum and internal brake mechanism. The caster type wheels require a smooth hard surface to roll upon , so as to retain parallelism and alignment of the duals and wheel hub with the axle. A problem arises when the concrete slab and/or steel plate is not parallel with the axle, wheel bearing and oil seal. Inclination of the truck axle is inherent when lifted at one side by a jack, and the angular displacement when lifted is difficult to compensate for and adversely affects reassembly due to inherent misalignment. Furthermore, lateral alignment cannot be assured, and this is the primary cause of bearing, oil seal and thread damage during re-assembly. Therefore, it is an object of this invention to attach a brake mechanism access apparatus directly to the truck or trailer axle to coaxially cantilever therefrom.
An alternate method of removal of a set of duals, without the use of the aforesaid Wheel Dolly, is to park the duals upon a smooth hard surface such as a concrete slab or sheet of steel. A jack is placed under the truck axle in order to raise the duals high enough to smear a layer of heavy oil or grease beneath the tires. The jack is then lowered so as to permit the tires to carry the weight of the duals, and with the brake adjustment backed off and the outer wheel bearing removed, the dual wheel assembly is slid on said oil or grease and off the axle or spindle. This method is resorted to at a place of breakdown and is often performed by road-side service. However, this alternate method is messy and inadvisable, since oil or grease and brake lining do not mix. Furthermore, alignment of the oil seal and wheel bearing with the axle or spindle is not ensured and in fact unlikely to be attained. In practice, horizontal and vertical alignment is visual through the center of the hub while pushing the duals back onto the axle or spindle. Also, the axis of the hub assembly is often eccentric with respect to the axle or spindle due to likely rotation of the dual wheel assembly of either or both tires, and because one tire is often smaller than the other. Tire wear, cupped treads and tire air pressure also affects alignment. And, missalignment is the primary cause of damage to the seal, wheel bearings and axle or spindle threads during re-assembly.
On newer trucks fitted with outboard hubs, the hub does not have to be removed in order to gain access to the brake drum and internal brake mechanism. However, this improvement over inboard hubs is still awkward and the wheel bearings and oil seal are not exposed to be inspected and/or repaired, unless the wheel hub is removed. The proceedure for gaining access to the wheel bearings and oil seal is solved with the present invention by raising the dual wheels off the ground, removing the wheel or dual wheels, and then by removing the inner lug nuts. With the truck brake slack adjuster backed off the brake drum can then be removed to expose the hub and removal of the wheel bearing lock-nut assembly, followed by removal of the outer wheel bearing then the hub and inner wheel bearing, thereby exposing the oil seal for inspection and/or repair (replacment),it being an object of this invention to provide access to both the outer and inner wheel bearings and particularly to the innermost oil seal. With the present invention, access to all parts of the hub, wheel bearings and brake assembly is attained, regardless of the type of commonly employed truck axles.
It is an object of this invention to temporarily remove a wheel or dual wheels laterally from an axle or spindle and to support the same in coaxial alignment therewith, preparatory to re-assembly. In carrying out this invention, the truck axle or spindle is extended by a rail member coaxially affixed thereto and upon which a carriage is releasably adapted to the wheel or dual wheels of the truck. In practice, there is an adapter affixed to the carriage and releasably secured to the wheel studs, for removal of the wheel and brake drum, so as to expose the internal brake mechanism and its shoes. Thimble lug nuts are used for extension of the studs to attain this attachment, whereby the carriage is enabled to transport the wheel and drum assembly out of and again into aligned position, and at all times in coaxial relationship with the axle or spindle.
It is another object of this invention to prevent rotation of the wheel or dual wheels when affixed to the carriage, and to this end the carriage is prevented from rotating upon the aforementioned extension rail upon which it travels laterally to and from the terminal end of the truck axle or spindle. In practice, the extension rail is polygonal, preferably rectangular in cross section, and over which the carriage travels upon supporting rollers and/or guides or the like.
The cantilevered rail is coaxially centered with respect to the axis of the truck axle or spindle and in practice is temporarily secured by threaded engagement to the existant end portion of said axle or spindle, replacing the normal lock nut assembly that retains the outer bearing. When lateral extension of the rail is brief, the rail can be totally cantilevered without additional support, for example when the wheel and drum assembly is removed at close range, and the carriage used for short travel and alignment only . However, when lateral transport is extreme (as shown in the drawings) for working access to the brakes and bearings and seal, then it is an object of this invention to stabilize the extension rail by providing a remote support which is vertically adjustable.
It is also an object of this invention to enable unobstructed access to the seals and bearings of the axle assembly, and to this end the aforesaid extension rail is removable from and replaceable upon the adapter that is left temporarily threaded onto the axle spindle. Accordingly, when the wheel or duals are removed onto the outer extending portion of the supporting rail, the inner end of the rail can be lifted out of its supported engagement on the adapter so as to be shifted away from the axle assembly, thereby to clear the area for inspection and/or work upon the seals and bearings.